Title: Microglia Activation and Gene Expression Alteration of Neurotrophins in the Hippocampus Following Early-Life Exposure to E-Cigarette Aerosols in a Murine Model.
Authors: Zelikoff, Judith T; Parmalee, Nancy L; Corbett, Kevin; Gordon, Terry; Klein, Catherine B; Aschner, Michael
Published In Toxicol Sci, (2018 03 01)
Abstract: Recent epidemiological data indicate that the popularity of electronic cigarettes (e-cigarettes), and consequently nicotine use, is rising in both adolescent and adult populations. As nicotine is a known developmental neurotoxin, these products present a potential threat for those exposed during early life stages. Despite this, few studies have evaluated the toxicity of e-cigarettes on the developing central nervous system. The goal of this study was to assess neurotoxicity resulting from early-life exposure to electronic cigarette aerosols in an in vivo model. Specifically, studies here focused on neuro-parameters related to neuroinflammation and neurotrophins. To accomplish this, pregnant and neonatal C57BL/6 mice were exposed to aerosols produced from classic tobacco flavor e-cigarette cartridges (with [13 mg/ml] and without nicotine) during gestation (∼3 weeks) and lactation (∼3 weeks) via whole-body inhalation. Exposure to e-cigarette aerosols with and without nicotine caused significant reductions in hippocampal gene expression of Ngfr and Bdnf, as well as in serum levels of cytokines IL-1β, IL-2, and IL-6. Exposure to e-cigarette aerosols without nicotine enhanced expression of Iba-1, a specific marker of microglia, in the cornus ammonis 1 region of the hippocampus. Overall, our novel results indicate that exposure to e-cigarette aerosols, with and without nicotine, poses a considerable risk to the developing central nervous system. Consequently, e-cigarettes should be considered a potential public health threat, especially early in life, requiring further research and policy considerations.
PubMed ID: 29161446
MeSH Terms: Administration, Inhalation; Aerosols/toxicity*; Animals; Animals, Newborn; Cytokines/blood; Electronic Nicotine Delivery Systems*; Female; Gene Expression Profiling; Hippocampus/drug effects*; Hippocampus/growth & development; Hippocampus/metabolism; Mice, Inbred C57BL; Microglia/drug effects*; Microglia/immunology; Microglia/metabolism; Nerve Growth Factors/genetics*; Nicotine/toxicity; Pregnancy; Prenatal Exposure Delayed Effects/chemically induced*; Prenatal Exposure Delayed Effects/metabolism; Transcriptome/drug effects*